Spark plug



Patented July 1, 1924.

UNITED STATES LEO B. GOETZ, OF WEXFO'RD, PENNSYLVANIA.

sranx PLUG.

Application led October 27, 1919. Serial No. 333,532.

To all whom 5t may concern.'

Beit lmown that I,l LEO R. Gon'rz, a citizen of the United States,residing at Wexford, in the county of Allegheny and State ofPennsylvania, have invented certain new and useful Improvements in SparkPlugs, of which the following is a specification.

My invention consists of an improvement in spark plugs for ignition ofthe charge in internal combustion engines. comprises a primary andsecondary electrode or a terminal electrode and a brake electrode inalignment therewith, capable of adjustment towards and from the primary,whereby to provide an adjustable spark gap. The object in this respectis, as usual in similar devices, to provide an energizer inconnectionwith the ignition circuit, at a. point remote from the sparkingterminals for energizing or increasing the size of the spark; also toprevent short circuit at the sparking contacts due to accumulation of.

carbon or other foreign matter.`

The device as a whole is entirely self-contained, composed of a minimumof parts, and is also'provided with a novel spark terminal integralmember divided into a plurality of individual points in operative,relation to the coacting electrode. Other features of the inventionwill be chamber ;/l

Fig. 2 is a similar view but showing the spark plug in central verticalsection;

F1 3 1s an inner end view of the device showlng the .divided or pluralterminal sparking end;

Fig. 4 is a cross sectional view on the line IV-IV Aof Fig. 2; and lFig. 5 is a partial sectional detail view of the inner end of the plugindicated bythe section line V-V of Fig. 3;

In the drawings, A indicates the' endl portion of an ordinary internalcombustion engine, into the explosion chamber of which the spark plug Bprojects by its terminals 2.

These terminals are integral with the main body portion of the plug Bwhich may be of iron, steel, or other suitable metal and which has anopening extending there- The device.

through, the opening at the terminal end being much less in diameterthan the opening at the opposite end, whereby the end of the body B issubstantially solid, but has a central opening of relatively smalldiameter therethrough and is slotted, as indicated,

to form the terminals 2. Terminals 2 arein operative relation to thesparking electrode 3, centrally arranged of the inner portion ofterminating slightly beyond the terminal of the adjustable breakelectrode 4, as indicated at b. Electrode 4 extends upwardly through theupper portion of the plug and is provided with a tightening thumb screw5 by which the current supplying terminal 6 is secured between nut -5and an inner adjusting nut 7. The upper portion of electrode 4 isthreaded, as indicated, and its outer terminal 8 is squared orflattened, 'or otherwise shaped, to admit of engagement by a suitableturning tool, as pliers, whereby to adjust the electrode, by itsthreaded engagement, with a tapered terminal coping or nut 9. Said nut,as shown, is of coniform shape, and tits upon the upper end of acylindrical insulating plug 10, through which the electrode extends, asshown. The inner body port-ion of plug 10 is cylindrical, and isembraced by a nut 11 threaded into the interior of the main plug memberB, the inner end of the nut bearing against an inner terminal iange 12of plug 10, clamping it directly against the inner portion of the plugand fiXedly positioning the parts, as clearly shown in Fig. 2.

The inner sparking electrode 3 is centrally mounted, and extends throughan insulating body or mass of mica disks 13 in laminated arrangement,tightly set within a receiving cavity in the inner middle p0rtionof theplug, under great pressure, and xedly holding the electrode 3 inposition, with its terminal 14 projecting beyond the insulating mica andin operative relation to the spark plug terminal members 2, as indicatedin Figs. 2 and 5 respectively. The inner portion of the plugbody B ispreterably chamfered or beveled, as indicated edges for the mica diskswhich, as shown, are in upper and lower sets of varying diameter. Suchconstruction is not, however, absolutely essential, and is incident tothe general sectional area within the surrounding outer body portion ofthe plug.

65 the plug, as shown, and with its inner end at 15, and also at 16,providing bearing The terminals 2 are, as stated, integral with the plugmember B, extending beyond lit in rounded formation, as shown, and aredivided by transverse intervening slots 17, the inner edges of theterminals 2 being preferably somewhat eoncaved or otherwise sloped awayfrom each other at `their inner portions, as indicated at 18. Theshoulder formed by the upper part of the terminals serves to engage theinsulating disks to retain them in position.

In operation, the adjustable electrode 4 may be 'very accurately set byits upper threaded portion, in nut 9, and iXedly held therein by thelock nut 7 which, as shown, telescopes slightly over the upper taperedportion ofthe nut, whereby to very tightly hold the electrode inadjusted position with relation to the inner terminal of the sparkelectrode 3.- The spark gap b operates to provide means for energizingthe spark, as will be readily understood, resulting in any desiredincrease or diminution of the spark between theinner terminal ofelectrode 3 and either of the terminals 2.

The simplicity of the device greatly contributes to its operativenessand economy of manufacture, while the provision ofY the accurateadjustment of the coacting electrode and the construction of thesparking terminals greatly contribute to the eiciency and .continuousdependability of the resulting ignition.

It will be understood that the device may be changed or varied in detailconstruction, proportions or other features by the. skilled mechanic,but that all such changes are to be considered as within the scope ofthe following claim.

lVhat I claim is:

A spark plug comprising a metal body having acentral chamber therein, aplurality of integral radially disposed electrodes formed at the bottomof the metal body, and presenting shoulders at the inner end of thechamber, a central electrode in the body, al

plurality of transversely disposed micaJ disks in the chamber throughwhich the central electrode passes and by means of which it issupported, a clamping nut having a threaded engagement with the upperend of the body,

said disks, being confined between said shoulders of the radialelectrodes and the clamping nut, and a top member extending through thenut and having a flange at its lower end interposed between the nut andthe mica, said top member having a central conductor therein.

In testimony whereof I hereunto ax my signature.

LEO R. GOETZ.

